Observation of Topological Surface State in High Temperature Superconductor MgB2

 · Invited

Abstract

Most topological superconductors known-to-date suffer from low transition temperatures (Tc) and/or high fragility to disorder and dopant levels, which greatly hamper the progress in this promising field. In this work, we suggest BCS superconductor MgB2 as a superior candidate: not only is its superconducting Tc=39K nearly triple the current record of all candidate topological superconductors, but it also has topological Dirac nodal line states which are highly tolerant against disorder and inadvertent doping variations. Our density functional theory (DFT) calculation and Angle-resolved Photoemission Spectroscopy (ARPES) measurements locate the topological Dirac Nodal Lines and their corresponding topological surface states on the [010] faces of MgB2, which could host topological superconductivity via the proximity effect to the bulk.

*This work was funded by DOE project DE-FG02-03ER46066 (Colorado) and by the DOE project DE-FG02-04ER46148 (Utah). Work in the Stanford Synchrotron Radiation Lightsource is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

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Presenters

  • Xiaoqing Zhou

    • University of Colorado, Boulder

Authors

  • Xiaoqing Zhou

    • University of Colorado, Boulder

  • Kyle Gordon

    • University of Colorado, Boulder

  • Kyung-Hwan Jin

    • Physics, University of Utah
    • Department of Materials Science and Engineering, University of Utah
    • University of Utah

  • Haoxiang Li

    • University of Colorado, Boulder

  • Dushyant M Narayan

    • University of Colorado, Boulder

  • Hengdi Zhao

    • Department of Physics, University of Colorado, Boulder CO 80309
    • Department of Physics, University of Colorado, Boulder, CO 80309
    • Department of Physics, University of Colorado at Boulder
    • University of Colorado, Boulder

  • Hao Zheng

    • Department of Physics, University of Colorado, Boulder CO 80309
    • Department of Physics, University of Colorado, Boulder, CO 80309
    • Department of Physics, University of Colorado at Boulder
    • University of Colorado, Boulder

  • Huaqing Huang

    • Department of Materials Science and Engineering, University of Utah
    • University of Utah
    • Physics, University of Utah

  • Gang Cao

    • Department of Physics, University of Colorado-Boulder
    • Department of Physics, University of Colorado, Boulder CO 80309
    • Department of Physics, University of Colorado, Boulder, CO 80309
    • Department of Physics, University of Colorado at Boulder
    • Physics and Astronomy, University of Kentucky
    • University of Colorado, Boulder
    • University of Colorado Boulder

  • Nikolai D Zhigadlo

    • University of Bern

  • Feng Liu

    • Physics, University of Utah

  • Daniel Dessau

    • University of Colorado, Boulder